Electric control device with improved contact structure



Dec. 8, G. JAKEL ELECTRIC CONTROL DEVICE WITH IMPROVED CONTACT STRUCTURE Original Filed Oct 26, 1959 4 Sheets-Sheet 1 Fig.3 Fig. 4

Dec. 8, 1964 G. JAKEL 3,160,730

ELECTRIC CONTROL DEVICE WITH IMPROVED CONTACT STRUCTURE Original Filed Oct. 26, 1959 4 Sheets-Sheet 2 Fig. 6

44 1 lmUm [:1 I m a E] 15: IE] IE I a: El E1 WITNESSES INVENTOR KM, Gustave J'kel ATTORNEY G. JAKEL 3,160,730

ELECTRIC CONTROL DEVICE WITH IMPROVED CONTACT STRUCTURE Dec. 8, 1964 4 Sheets-Sheet 3 Original Filed Oct 26, 1959 Dec. 8, 1964 e. JAKEL 3,160,730

ELECTRIC CONTROL DEVICE WITH IMPROVED CONTACT STRUCTURE Original Filed Oct. 26, 1959 4 Sheets-Sheet 4 I25 Fig. II

57 so I V 5| l 32 |l30 J 1% r United States Patent f g This invention relates to electromagnetically operated switches, and more particularly to industrial con ractors, or relays, used in electric systems of control, wherein the contact assembly includes a plurality of movable contact members and a plurality of coacting stationary contact members.

This application is a division of application Serial No.

848,779, issued April 30, 1963 as Patent No. 3,088,058.

in most industrial applications compactness of the contactor is of great value and the useful life is of great value.

It is abroad object of this inventio'nto provide a contactor that is both compact and has a long useful life.

It is a more specific object of this invention to provide a control relay of minimum size but having a maximum number of bridge contacts of suitable current interrupting capacity, wherein the terminal connectors of the stationary contacts are so arranged as to be readily accessible in their assembled positions.

Another object of this invention is to provide a contactor which lends itself to many applications, particularly in control system, that is, to provide a type of contactor which permits one and the same contactor to be used both as a normal control device with terminal screws and mounted on a base, and also as an interchangeable element by utilizing, for example, plug-in connected bars, with a simultaneous reversal of the mounting position.

The invention attains the objects thus far expressed by constructing a contact chamber unit including the contact .bridge carrier and the magnet armature, to form an'interichangeable structural unit such that contact chambers having one bank of contacts as well as contact chambers having two banks of contacts can be selectively mounted,

regardless of the type of terminal connectors employed and regardless of the mounting position the contactor takes on a suitable base.

The objects recited are merely illustrative. Other objects and advantages become more apparent from a study of the following specification and the accordpanying drawings, in which:

FIGS. 1 and 2, with parts in section, show front and side elevations, respectively, of the simplest embodiment of this invention;

FIGS. 3 and 4, with parts in section, show front and side elevations, respectively, of a somewhat more com plex embodiment of this invention;

FIGS. 5 and 6 are showings similar to FIGS. 3 and 4 of a further embodiment of this invention; 7

FIG. 7 shows a plan view of a cover such as may b usedwith the embodiment shown in FIGS. 5 and 6;

FIG. 8 is an enlarged view of a. detail of this invention; FIG. 9 is an exploded view from the side of the stationary contact structure;

FIG. 10 is an exploded view from the front of the showing in FIG. 9; and

FIG. 11 is a plan view of the stationary contact.

The operating parts of the contactor are disposed in a housing 1 having the general shape of a right parallelopiped and comprising a bottom part 2 and a cap or top part 3, which parts are held firmly together as a unit ilfififidfi Patented Dec. 8, 1964 by the bolts 4 disposed at diagonal corners of the housing. An E-shaped main magnet, or core, 5 of laminations is disposed in the bottom part 2 with the legs of the E projecting upwardly. A magnetizing winding, or coil, 6, disposed on a suitable spool 7 of insulating material, is disposed over the middle leg 8 of the core 5. Near the bottom 9 of the core 5, that is, near the midpo-rtion or" the inner bottom of the part 2 when the magnet is in position, a relatively small rectangular hole, or opening, 14) is provided transversely of the core. A relatively narrow and thin but quite stifi rectangular bar 11 is disposed in the opening 10. The bar 11 has a downwardly directed bowed portion 12 near its midportion to engage with a line contact the middle of the upwardly facing surface forming the bottom boundary of the hole 10.

V The upwardly facing surface at the bottom of part 2 is provided longitudinally thereof with an arcuate ridge 13 in the shape of a relatively small segment of a cylinder. A flat rectangular strip 14 of waxed paper, hard rubber, hard neoprene, or other somewhat pliable, or resilient, material fits snugly in the part 2 against the arcuate' ridge 13 to engage this ridge with a line contact parallel to the axis of the ridge, or cylindrical segment 13. It will be noted that this line contact is parallel to the line contact made at the bottom of slot 10 by the downwardly directed bowed portion 12 on bar 11 and that the two line contacts are spaced but a short distance apart.

The downwardly facing flat surface of the magnet longitudinally engages the strip 14. The strip 14 is not an absolutely necessary part of this invention. If the strip 14 is not used then the magnet itself engages the arcuate ridge in a line longitudinally of the back of the magnet. a

The coil spool 7 is provided with shallow downwardly directed cup-shaped regions for receiving the upper ends of the springs 15 and 16. These springs are rather still, and with their lower ends rest on the ends of the bar 11. When the bolts 4 are positioned to firmly hold the parts 2 and 3 together, the magnet 5 is firmly biased downwardly against the arcuate ridge.

The upper end of the coil spool engages the top part 3 telescopically but against suitable shoulders so that the coil is firmly held against upward movement into the part 3 housing the contact assembly. The terminals for the coil are indicated at-17 and 18. These terminals are set in recesses and thus do not protrude beyond the general outline of the contactor.

The upper part 3 houses the contact assembly, the

From the foregoing disclosure of the mounting of the.

core 5, in relation to the bottom part, the coil, and the armature, it is apparent that the core 5 may, when necessary, perform tilting movements relative to the coil and the housing as well as with respect to the armature,

' which tilting movements thus adjust themselves to the Further, since the core 5 notactuflly rigidly mounted in the housing, it actually,

upon energization of the coil has some slight transient upward movement. The armature and magnet so to speak meet in mid-air land the impact is cushioned both by the movements and the strip 14. Also further since the arcuate ridge 13 contacts the core 5 ina line and the C9 tilting required is small the magnet after the first impact with the armature remains in its desired tilted position. There is thus, on successive operations, no edge impact between the armature and magnet and premature destruction of the magnet pole surfaces is eliminated. The contactor is thus less noisy and has a very much lengthened useful life.

Furthermore, it is not only possible to mount the core so as to permit it to perform certain tilting movement relative to the coil and housing by means of the bar 11 and associated parts and the arcuate ridge, but it is also possible to support the coil spool relative to the top part of the housing by means of suitably positioned extensions having the shape of rounded fins. For example, by so disposing the rounded fins on the supporting surface that the longitudinal axis thereof extends perpendicular to the longitudinal dimension of the magnet, said coil, and thus the magnet may also tilt in a direction perpendiuclar to the direction of tilt resulting from the bar 11 and associated parts and the arcuate ridge 13. In other words, in this case said coil and magnet would be tiltable in the housing toward both sides because the mounting acts like a Cardan mounting.

The contact-bridge carrier 19 is provided longitudinally thereof with an upwardly directed rectangularly shaped projection 22 provided with substantially rectangularly window-like transverse openings 23 for receiving the contact bridges 24, which are to coact with the stationary contact structures 25.

The windowlike openings 23 have recessed shoulders 28' at each outer vertical edge for receiving the guiding ears 28 of the U-shaped holders 27. A spring 29 is disposed between the facing bights of each two of the U-shaped holders to urge them upwardly and downwardly, respectively, to hold the contact bridges disposed between the holders 27 and the top and bottom ends of the opening. Since the projecting ears on the holders retain the holders against transverse movement in the window-like openings 23 it is apparent that the contact bridges may be readily removed and re-inserted. This removal is readily effected by merely pulling the contact bridge out. For insertion the contact bridge is merely pushed in position. The insertion may be so made that any particular contact bridge may be a make contact or a break contact.

In this switch each contact bridge 24 coacts with two stationary contact structures disposed respectively between corresponding facing ends of a pair of side walls 50 and 51, which together with the bottom 52 between each pair of side walls form contact chambers for each pair of stationary contact structures 25 and one contact bridge 24. In Fig. 8 only the front stationary contact 125 is shown.

A discussion of the structure, mounting, disposition etc., of one stationary contact structure 25 with respect to one contact bridge 24 will suffice to'understand the entire contact assembly. V

The stationary contact structure 25 includes an element E having the general shape of a turtle, having a body portion 53, a head 54 having a contact 125 secured thereto, feet 30, 31, 130 and 131, and a tail 34.

The side walls 50 and 51 at corresponding facing ends are provided with the relatively narrow parallel facing grooves 32 and 132, the grooves being also parallel to the bottom 52. A cylindrical well 36 is disposed in the bottom between the grooves near the ends of the facing side Walls.

The feet 30 and 31 frictionally engage the groove 32 at both horizontal surfaces and preferably also the vertical surface, and feet 130 and 131 frictionally engage the groove 132' at both horizontal surfaces and preferably also the vertical surface. This means, when the stationary contact structure is in its desired position, the element E has firm horizontal transverse stability and firm vertical stability. The frictional engagement the feet make with the grooved walls gives the element E some horizontal longitudinal stability.

The tail 3 is crimped down almost at right angles to the body portion 52 so that its inner flat end cooperates with the corner of the hexagonal nut disposed below the stationary contact structure. The flat portions of the nut fit between the side walls, whereby the nut is kept from turning during assembly and dissassembly of the parts. The tail 34 is thus a keeper for the nut and assures that the axis of the threaded opening of the nut during assembly is held substantially in alignment with the axis of the well 36. I

A centrally apertured arched conductor clamp 55 is disposed below the bolt head and above the body portion 53. An apertured strip of conducting material 56 is disposed on the back of the body portion 53. This strip is narrow enough to fit between the arches of the feet 30 and and at its irmer end, a short distance beyond the bolt opening, has the upwardly bent portion 57. This portion 57 provides a stop for the conductor end to limit the distance a conductor can be inserted when the conductor is slipped under the clamp 55 for connection of the conductor to the stationary contact structure.

The threaded bolt 35, without threaded engagement passes through the clamp 55, the strip 56, the mid-part of the body portion 53 and is threaded into nut 33. Below the nut 33, which nut 33 rests on the bottom surface of the contact chamber, the lower end of the bolt extends without threaded engagement, but without any material play or looseness, into the smooth cylindrical well, or opening, 36 to thus provide firm horizontal longitudinal stability to the element E. In short all elements directly associated with the stationary contact structure are held in position. There is thus no chance of accidental loss of any of the parts.

In assembling the parts, particularly in the field where no helpful. jigs are available, the parts may be placed on the bolt in the arrangement shown with the bottom end .of the bolt not projecting below the nut 33. Thus assembled the parts may be pressed into position so that the feet 30, 31, 130 and 131 frictionally slip into the grooves 32 and 132 and then the bolt threaded down sufiiciently so that its lower end extends into the well, or opening, 36.

The resetting of the armature and therefore the contact-bridge carrier is effected by diagonally displaced springs 37 and 38 which abut against the coil spool and the contact-bridge carrier.

FIGS. 3 and 4 are front and side elevations, respectively, of a contactor built according to the invention, wherein a contact member having two superimposed rows of contacts is employed instead of the single-row contact chamber with the associated contact-bridge carrier illustrated in FIGS. 1 and 2. In FIGS. 3 and 4 there can be seen the connecting means 4 between the magnetic housing 2 and housing 303 mounted thereon as well as the fastening means 39-provided on the base. The contact housing 303 is extended toward the side remote from the magnet core andaccommodates a second row of contacts comprising the stationary contact structure 340, the associated contact bridges :324, and the stationary terminal connectors'325. From FIG. 4 it can be seen that, by Way of comparison with the arrangement in FIGS. 1 and 2, the stationary contact structure 25 in the lower row has its head 52 connected by a goose-neck construction to be disposed above the contact bridges 24 and are thus arranged so as to cooperate with reversed contact bridges 24 to form break contacts instead of the make contacts illustrated in FIG. 2; It can also be seen that the heads 52 are displaced toward the inside of the contact chambers with respect to the elements 25, which arrangement makes the heads easily accessible.

j FIGS. 5 and 6 show a further embodiment of the contactor according to the invention, wherein the stationary contacts with the clamping type terminals have been replaced by knife-type contact studs 41 disposed in the same housing portion. FIGS. 5 and 6 further show the connection of the contactor, provided with contact studs, with a terminal board 42. It will be noted hat the position of the assembly has been reversed with respect to the base-type mounting, previously described, on account of the arrangement of the fixed contacts on the terminal board 42. The contactor is secured to the terminal board 42 which is provided with resilient clamps 43. These clamps ensure a proper and firm mounting of the contactor on the base support. FIGS. 5 and 6 further show that the contact chamber region is provided with a cover 44 having openings 44 therein for guiding and holding the contact studs 41.

In order to prevent the contact studs from being inadvertently interchanged with respect to said cover, and the contactor from being incorrectly attached to the terminal strip, the housing portion 503, the cover 44, and

the terminal board 42 are provided with projections and recesses associated therewith, said projections and recesses being asymmetrically disposed with respect to each other in amanner known per se. The same is true with respect to the magnet housing 2 and the housing portion 593. The stationary clamping-type terminals and the plug-in type terminal studs are so constructed that they can be interchanged, utilizing the same housing portion 503.

FIG. 7 is a plan view of said cover 44 which preferably is made of transparent plastic. Since additional knife contacts are needed for the trip coil terminals, a short Wire connection 45 is provided between the terminal connector 17 and one of said stationary contacts. It will be noted that, by using knife contacts with a contactor constructed according to the invention, there may be used a maximum of only seven closing contacts or four closing contacts and three opening contacts, respectively, instead of the eight closing contacts or four closing contacts and four opening contacts, respectively, otherwise possible.

It is to be understood that various modifications are possible with respect to the design of the magnet, the use of multi-legged magnets, the construction of the coil body, and, if desired, the configuration of said scalebeam shaped lever as well as with respect to the arrangement of these elements, without departing from the scope of the invention.

I claim as my invention: 7

1. In an electric control device, a contact assembly comprising, in combination, a housing having a pair of spaced side walls provided with parallel grooves, a first stationary contact assembly comprising a contact piece having an'opening therein, said contact piece comprising frictional engaging means at each of two opposite sides thereof, said contact piece being positioned with said frictional engaging means being in frictional engagement in said parallel grooves, a bolt passing through said open ing to provide an interconnection between the contact piece and a suitable circuit lead, said bolt projecting into an opening in the housing to thus prevent dislodgement of the contact piece, a second similar stationary contact assembly disposed in opposed spaced relation to the first, a resiliently mounted contact bridge disposed to bridge said contact pieces, and means for actuating the. contact bridge.

2. In an electric control device, a switching assembly comprising in combination, a housing having a pair of spaced parallel side walls provided with parallel facing grooves, a first stationary contact assembly comprising a contact piece provided with resilient ears at its outer edges to resiliently engage the grooves to hold the contact piece in position, and a circuit connecting bolt disposed transversely of the contact piece through a hole in the contact piece, said bolt extending beyond the contact piece into a hole in the housing to prevent dislodgernent of the contact piece, a second similar stationary contact assembly disposed in opposed relation to the first contact assembly, a resiliently mounted contact bridge disposed to bridge the contact pieces, and means for actuating the contact bridge.

3. The arrangement as claimed in claim 2 wherein the means for actuat ng the contact bridge comprises a contact bridge carrier having a generally rectangular projection guidably received in the housing and wherein the projection is provided with a window-like opening having guiding ledges on the side, a contact bridge holder comprising apair of facing U-shaped members having ears at each of the corners of the legs of the U-shaped members for engaging the guiding ledges, a spring between the facing U-shaped members to force, or bias, the U-shaped members toward the ends of the windowlike openings, and a contact bridge disposed transversely of the window-like openings between the back portion of the b ight of at least one of the U-shaped members.

4. In an electric control device having a pair of spaced stationary contacts and a contact bridging member movable toward said stationary contacts to bridge them and away to interrupt the bridging action, the subcombination of, an insulating member having a pair of parallel facing grooves, a flat surface between the grooves provided with a well, a contact member having a turtle-like shape comprising a body portion, a head portion and four feet, said feet being frictionally disposed in said grooves, said contact member having an aperture through its body portion for receiving a bolt, an apertured conductor clamp disposed under the head of the bolt, a nut disposed below the body portion of the contact member and over the well, and said bolt passing through the conductor clamp and the contact member and being threaded through the nut to extend into the well. i

5. In an electric control device having a pair of spaced stationary contacts and a contact bridging member movable toward said stationary contacts to bridge them and way to interrupt the bridging action, the subcombination of, an insulating member having a pair of parallel facing grooves, a fiat surface between the grooves provided with a well, a contact member having a turtle-like shape comprising a head portion, a body portion and four feet, one of said stationary contacts being disposed on said head portion, said feet frictionally engaging walls of the grooves, said contact member having an aperture through its body portion for receiving a bolt, an apertured conductor clamp disposed underthe head of the bolt, a nut disposed below'the' body portion of the contact member and over the well, saidbolt passing through the conductor clamp and the contact member without frictional engagement and being threaded through the nut to extend without frictional engagement into the well.

6. In an electric control device having a pair of spaced stationary contacts and a contact bridging member movable toward said stationary contacts to bridge them and away to interrupt the bridging action, the subcombination of, an insulating member having a pair of parallel facing grooves, a flat surface between the grooves provided with a well, a contact member having feet that frictionaliy engage the sides and bottoms of the grooves,

.saidcontact member having an aperture for receiving a bolt, an apertured conductor clamp disposed under -the head of the bolt, a nut disposed below the contact member and over the well, said bolt passing through the conductor clamp and the contact member without frictional engagement and being threaded through the nut to en'- tend into the well.

7. In an electric control device havin a pair of spaced stationary contacts and a contact bridging member movable toward said stationary contacts to bridge them and away to interrupt the bridging action, the subcombination of, an insulating member having a pair of parallel facing grooves; a flat surface between the grooves provided with a well, a contact member having feet that frictionally fit into the grooves to provide firm lateral and transverse stability to the contact member on the insulating member, said contact member having an aperture for receiving a bolt, a nut disposed below the contact member and over the well, said bolt passing through the contact member without threaded engagement and being threaded through the nut to extend into the well to thus provide firm longitudinal stability to the contact member.

8. In an electric control device having a pair of spaced stationary contacts and a contact bridging member movable toward said stationary contacts to bridge them and away to interrupt the bridging action, the subcombination of, an insulating member having a pair of parallel facing grooves, a fiat surface between the grooves provided with a well, a contact member having a turtle-like shape comprising a head portion, a body portion and four feet, one of said stationary contacts being supported on said head portion, said feet frictionally fitting into the grooves to provide firm lateral and transverse stability to the contact member on the insulating member, said contact member having an aperture through its body portion for receiving a bolt, a nut disposed below the back portion of the contact member and over the well, said bolt passing through the contact member without threaded engagement and being threaded through the nut to extend without friction into the well to thus provide firm longitudinal stability to the contact member.

9. In an electric control device, in combination, a base of insulating material having a contact chamber comprising a bottom and a pair of spaced parallel side walls, a first stationary contact disposed near one pair of the two corresponding ends of the side walls, a second stationary contact disposed near the other pair of the two corresponding ends of the side wall, a contact bridging member, a carrier for the contact bridging member movable normal to the line between the stationary contacts to thus cause said contact bridging member to engage and disengage, depending on the direction of movement of the carrier, toward or away, with respect to the line between the stationary contacts, said carrier being of insulating material and having a window-like opening aligned between the stationary contacts with the opening being provided with recessed shoulders at all four longitudinal edges of the opening, a pair of U-shaped contact holders disposed in the opening at opposite ends thereof with the legs of the opposite contact holders directed toward each other, a

spring disposed between the contact holders to bias the holders against the ends of the opening, means on the holders engaging the shoulders to thus guide the holders, said contact bridging member being disposed between one end of the opening and one holder.

10. In an electric control device, in combination, a base of insulating material having a contact chamber comprising a bottom and a pair of spaced parallel side walls, a first stationary contact disposed near one pair of the two corresponding ends of the side walls, a second stationary contact disposed near the other pair of the two corresponding ends of the side walls, a contact bridging member, a carrier for the contact bridging member movable normal to the line between the stationary contacts to thus cause said contact bridging member to engage and disengage said stationary contacts, each of said stationary contacts having means for providing firm lateral, transverse, and longitudinal stability to the stationary contacts, said means comprising apair of parallel grooves in the corresponding facing ends of the side walls above the bottom and substantially parallel thereto, said stationary contact having feet at each of its sides that frictionally fit into the grooves to provide firm transverse and lateral stability to the stationary contact, a hole in the bottom between the grooves, a nut, and a bolt passing through a suitable hole in the stationary contact and threadedly en gaging the nut disposed over the hole, and the end of the bolt extending into the hole to provide firm longitudinal stability to the stationary contact.

11. In an electric control device, in combination, a base of insulating material having a contact chamber comprising a bottom and a pair of spaced parallel side walls, a stationary contact fixed on the bottom near one set of ends of the side walls, a similar stationary contact fixed on the bottom near the other set of ends of the side walls, a bridging contact member having contact surfaces engageable with and disengageable from said stationary con tacts, a movable carrier disposed between the stationary contacts, said carrier having a window-like opening aligned with the space between the side walls, said opening having recessed shoulders at each outer longitudinal edge, a pair of U-shaped contact holders disposed in the opening one at each end of the opening with the legs of the opposite holders pointing toward each other, each leg having a projection at each side that fits against one of the recessed shoulders to guide the holders in the opening, a spring disposed between the holders to bias the holders toward opposite ends of the opening, said bridging contact member being disposed between one end of the opening and the outer surface of the bight portion of one of the U-shaped holders, whereby the bridging contact member is resiliently held in the opening in the carrier, and upon movement of the carrier normal to the bottom and between the side walls'said bridging contact member coacting with the stationary contacts,

12. In an electric control device a pair of spaced stationary contacts and a contact bridging member movable toward and away from said stationary contacts, the subcombination, of a carrier of insulating material for the contact bridging member, said carrier being provided with a window-like opening having recessed shoulders along its longitudinal edges, a U-shaped contact holder having four projections on the sides of the legs two projections engaging the recessed shoulders in one face of the opening and the other two projections engaging the recessed shoulders of the other face of the opening, a spring disposed between the legs of the U-shaped contact holder, and backup means for the spring on the holder to thus bias the holder in the direction of one end of the window- .like opening, said contact bridging member being disposed between the contact holder and one end of the windowlike opening.

13. In an electric control device having a pair of spaced stationary contacts and a contact bridging member movable toward and away from the stationary contacts, a plate-like carrier of insulating material of a selected thickness disposed to move transverse of the line between the stationary contacts, said carrier being provided with a window-like opening having a recessed shoulder in each of its four longitudinal edges, a U-shaped contact holder having four projections fitting into the four recessed shoulders to thus guide the movement of the contact holder longitudinally of the window-like opening, said holder having the legs of the U projecting away from one end of the window-like opening so that the outer surface of the bight of the U is adjacent said one end of the window-like opening, a spring disposed between the legs References Cited in the tile of this patent UNITED STATES PATENTS 2,310,334 Wilson Feb. 9, 1943 2,924,685 Burch Feb. 9, 1960 FOREIGN PATENTS 608,960 Great Britain Sept. 23, 1948 

1. IN AN ELECTRIC CONTROL DEVICE, A CONTACT ASSEMBLY COMPRISING, IN COMBINATION, A HOUSING HAVING A PAIR OF SPACED SIDE WALLS PROVIDED WITH PARALLEL GROOVES, A FIRST STATIONARY CONTACT ASSEMBLY COMPRISING A CONTACT PIECE HAVING AN OPENING THEREIN, SAID CONTACT PIECE COMPRISING FRICTIONAL ENGAGING MEANS AT EACH OF TWO OPPOSITE SIDES THEREOF, SAID CONTACT PIECE BEING POSITIONED WITH SAID FRICTIONAL ENGAGING MEANS BEING IN FRICTIONAL ENGAGEMENT IN SAID PARALLEL GROOVES, A BOLT PASSING THROUGH SAID OPENING TO PROVIDE AN INTERCONNECTION BETWEEN THE CONTACT PIECE AND A SUITABLE CIRCUIT LEAD, SAID BOLT PROJECTING INTO AN OPENING IN THE HOUSING TO THUS PREVENT DISLODGEMENT OF THE CONTACT PIECE, A SECOND SIMILAR STATIONARY CONTACT ASSEMBLY DISPOSED IN OPPOSED SPACED RELATION TO THE FIRST, A RESILIENTLY MOUNTED CONTACT BRIDGE DISPOSED TO BRIDGE 